Acidic pH Values Research Articles

Cationic polyelectrolytes prevent the aggregation of l-lactate dehydrogenase under unstable conditions

Unstructured biological macromolecules have attracted attention as protein aggregation inhibitors in living cells. Some are characterized by their free structural configuration, highly charged, and water-soluble. However, the importance of these properties in inhibiting protein aggregation remains unclear. In this study, we investigated the effect of charged poly (amino acids), which mimic these properties, on aggregation of l-lactate dehydrogenase (LDH) and compared their effects to monomeric amino acids and folded proteins. LDH was stable and active at a neutral pH (~7) but formed inactive aggregates at acidic pH (< 6). Adding cationic polyelectrolytes of poly-l-lysine and poly-l-arginine suppressed the acid-induced aggregation and inactivation of LDH under acidic pH values. Adding monomeric amino acids and cationic folded proteins also prevented LDH aggregation but with lower efficacy than cationic polyelectrolytes. These results indicate that unstructured polyelectrolytes effectively stabilize unstable enzymes because they interact flexibly and multivalently with them. Our findings provide a simple method for stabilizing enzymes under unstable conditions.

Assessing the physicochemical parameters of leachate from biowaste fractions in a laboratory setting, using the elusion method

Leachate emissions, which are regarded as one of the primary polluters of groundwater and the environment, are unavoidable side effect of landfill operation. The leachate includes hazardous chemicals, heavy metals, suspended particles, and soluble organic molecules. The objective of this study was to simulate the leachate quality from the biowaste and assess its impact on groundwater pollution in a laboratory setting. For laboratory analysis, a variety of waste fractions that make up the waste composition of household bins in Windhoek were collected and mimicked in the laboratory for analysis. The aim of modeling these scenarios in the laboratory was to examine the quality of the leachate in the eluate when substantial volumes of biowaste were added to the residual samples. The analysis was carried out in accordance with the German Institute for Standardization's (DIN 12457) with respect to the process for sampling strategy and sample preparation. From the laboratory analyses, the values of pH decreased from 6.9 to 4.4 as the biowaste was increasing from 0 to 100 %, while EC was increasing with the increase in biowaste input from 0.6 to 4.99 mS/cm; equally, the concentrations of COD were increasing with the increase of biowaste input from 643 to 24,616 mg/l. These parameters had the strongest influence on the properties of leachate, as the high level of COD indicates the presence of high level of organic strength and a sign of organic pollution. The low or acidic pH values were also as a result of the production of volatile organic acids, which can cause the landfill leachate of such a nature to enhance pH of drinking water and contribute in trihalomethane formation which is a toxic substance for human health. High values of EC on the other hand indicate the discharge or other sources of pollution that has lowered the water body’s relative quality. From the findings, it can be concluded that leachate in this study is biodegradable and un-stabilized, as shown by the low pH levels and high COD concentrations. It also alluded that a change in physicochemical parameters, regardless of how little the concentration is, has the ability to change the quality of groundwater. According to this study, leachate was highly contaminated with organic matters. This has proven that the more biowaste inputs, the higher the concentrations of the physicochemical metrics, which can then alter the quality of groundwater. Hence, a recommendation for organic waste to be diverted from landfill sites or treated before landfilled. The findings from the leachate and groundwater samples of the Kupferberg showed that the landfill is mature methanogenic and stabilized stage, when compared to the pH of the laboratory results. COD values in the leachate samples are way higher than the permissible limit of the Namibian standard guidelines for drinking water, as well as the WHO guidelines. As alluded to by many researchers, high COD concentrations indicate high organic strength and pollution. Just as observed in the laboratory, conductivity is equally high in the leachate samples of the Kupferberg landfill, indicating high salts or dissolved inorganic components. This study can conclusively say that there is a relationship between the observed laboratory results and the actual field results, because of the similar trends they portray, noting that the filed values are always higher than the laboratory values. Hence, a proper correlation method is recommended.

Biocompatible Rhamnolipid Self-Assemblies with pH-Responsive Antimicrobial Activity.

There is an urgent need for alternative antimicrobial materials due to the growing challenge of bacteria becoming resistant to conventional antibiotics. This study demonstrates the creation of a biocompatible pH-switchable antimicrobial material by combining bacteria-derived rhamnolipids (RL) and food-grade glycerol monooleate (GMO). The integration of RL into dispersed GMO particles, with an inverse-type liquid crystalline cubic structure in the core, leads to colloidally stable supramolecular materials. The composition and pH-triggered structural transformations are studied with small-angle X-ray scattering, cryogenic transmission electron microscopy, and dynamic light scattering. The composition-structure-activity relationship is analyzed and optimized to target bacteria at acidic pH values of acute wounds. The new RL/GMO dispersions reduce Staphylococcus aureus (S. aureus) populations by 7-log after 24h of treatment with 64µg mL-1 of RL and prevent biofilm formation at pH = 5.0, but have no activity at pH = 7.0. Additionally, the system is active against methicillin-resistant S. aureus (MRSA) with minimum inhibitory concentration of 128µg mL-1 at pH 5.0. No activity is found against several Gram-negative bacteria at pH 5.0 and 7.0. The results provide a fundamental understanding of lipid self-assembly and the design of lipid-based biomaterials, which can further guide the development of alternative bio-based solutions to combat bacteria.

Electrochemical degradation of ciprofloxacin from water: Modeling and prediction using ANN and LSSVM

Ciprofloxacin is a widely used antibiotic that is also a persistent contamination that causes major health and environmental risks. This study investigated the electrochemical removal of ciprofloxacin using a boron-doped diamond anode and a non-supportive electrode to get an accurate understanding of the anode's performance. The effects of current density, initial ciprofloxacin concentration, time, pH, and electrolyte concentration on the removal efficiency of ciprofloxacin were investigated. Additionally, ANN and LSSVM models were used to predict ciprofloxacin removal. The results showed that the BDD anode was effective in removing ciprofloxacin from water, with complete removal of 10 mg L−1 CIP in less than 45 min with electrolyte concentration of 25 g L−1, a current density of 20 mA cm−2, and a pH value of 3. The removal efficiency was found to increase with increasing current density and time because it increases the concentration of active species. The removal efficiency was also found to be higher at acidic pH values and higher electrolyte concentrations. The ANN model was found to be more accurate in predicting ciprofloxacin removal than the LSSVM model, with an R2 of 0.9982 and an AARE% of 2.68%, compared to R2 of 0.9978 and an AARE% of 3.85%. The models were validated using a new set of data, and the results showed that the ANN model was able to accurately predict ciprofloxacin removal under a variety of conditions.

Unraveling the Intertwined Effect of pH on Helicobacter pylori Motility and the Microrheology of the Mucin-Based Medium It Swims in.

The gastric pathogen, Helicobacter pylori bacteria have to swim across a pH gradient from 2 to 7 in the mucus layer to colonize the gastric epithelium. Previous studies from our group have shown that porcine gastric mucin (PGM) gels at an acidic pH < 4, and H. pylori bacteria are unable to swim in the gel, although their flagella rotate. Changing pH impacts both the rheological properties of gastric mucin and also influences the proton (H+)-pumped flagellar motors of H. pylori as well as their anti-pH sensing receptors. To unravel these intertwined effects of acidic pH on both the viscoelastic properties of the mucin-based mucus as well as the flagellar motors and chemo-receptors of the bacterium, we compared the motility of H. pylori in PGM with that in Brucella broth (BB10) at different pH values using phase contrast microscopy to track the motion of the bacteria. The results show that the distribution of swimming speeds and other characteristics of the bacteria trajectories exhibit pH-dependent differences in both media. The swimming speed exhibits a peak at pH 4 in BB10, and a less pronounced peak at a higher pH of 5 in PGM. At all pH values, the bacteria swam faster and had a longer net displacement in BB10 compared to PGM. While the bacteria were stuck in PGM gels at pH < 4, they swam at these acidic pH values in BB10, although with reduced speed. Decreasing pH leads to a decreased fraction of motile bacteria, with a decreased contribution of the faster swimmers to the distributions of speeds and net displacement of trajectories. The body rotation rate is weakly dependent on pH in BB10, whereas in PGM bacteria that are immobilized in the low pH gel are capable of mechano-sensing and rotate faster. Bacteria can be stuck in the gel in various ways, including the flagella getting entangled in the fibers of the gel or the cell body being stuck to the gel. Our results show that in BB10, swimming is optimized at pH4, reflecting the combined effects of pH sensing by anti-pH tactic receptors and impact on H+ pumping of flagellar motors, while the increase in viscosity of PGM with decreasing pH and gelation below pH 4 lead to further reduction in swimming speed, with optimal swimming at pH 5 and immobilization of bacteria below pH 4.

Aerosol assisted synthesis of a pH responsive curcumin anticancer drug nanocarrier using chitosan and alginate natural polymers

In recent years, several nanocarrier synthesis methods have been developed. In cancer therapy, the use of smart nanocarriers is of interest. Smart nanocarriers respond to their environment and can release their cargo in a controlled manner under the action of internal or external stimuli. In this work, we report on the development of an aerosol-assisted method for the synthesis of curcumin-loaded chitosan/alginate-based polymeric nanocarrier (CurNCs). A custom-fabricated multi-nebulizer system was utilized for the synthesis of CurNCs. The developed system comprises three main parts a sprayer, an electric heater tunnel, and a collector. Curcumin and chitosan solutions were sprayed using a pneumatic multinebulizer into the electric heater tunnel to form chitosan-curcumin assemblies. Then, the aerosol was guided into the collector solution containing sodium alginate and tri-poly phosphate aqueous solution for further cross-linkage. The synthesized CurNCs were characterized using TEM, DLS, and FTIR techniques. The TEM size of the nanoparticles was 8.62 ± 2.25 nm. The release experiments revealed that the nanocarrier is sensitive to the environment pH as more curcumin is released at acidic pH values (as is the case for cancerous tissues) compared to physiological pH. The curcumin content of the nanocarrier was 77.27 mg g−1 with a drug loading efficiency of 62%. The in-vitro cytotoxicity of the synthesized nanocarrier was evaluated against the MCF7 breast cancer cell line. The IC50 concentrations for CurNCs and curcumin were obtained as 14.86 and 16.45 mg mL−1, respectively. The results showed that while the empty nanocarrier shows non-significant cytotoxicity, the CurNCs impact the cell culture and cause prolonged cell deaths. Overall, pH-responsive curcumin polymeric nanocarrier was synthesized using a custom fabricated aerosol-based method. The method enabled fast and feasible synthesis of the nanocarrier with high efficiency.

An innovative nanoformulation utilizing tumor microenvironment-responsive PEG-polyglutamic coating and dynamic charge adjustment for specific targeting of ER stress inducer, microRNA, and immunoadjuvant in pancreatic cancer: In vitro investigations

Pancreatic ductal adenocarcinoma (PDAC) is a significant obstacle to lowering global cancer deaths. CB-5083, a novel valosin-containing protein (VCP)/p97 inhibitor that disrupts proteasomal degradation and induces endoplasmic reticulum stress (ERS) accumulation, was evaluated as an inducer of immunogenic cell death (ICD) in PDAC treatment. Furthermore, miR-142 enhances checkpoint blockade and promotes M1 repolarization, while Toll-like receptor 7/8 agonist resiquimod (R) acts as an immunoadjuvant to amplify the immune response to miR-142. This research signifies the first integration of CB, miR-142, and R in solid lipid nanoparticles (SLNs) modified with peptides targeting PD-L1, EGFR, and ER, which were shelled by the PEG-polyglutamic (PGA) coating that detaches in response to the acidic pH values in the tumor microenvironment (TME). The modified SLNs exhibited pH-sensitive cytotoxicity against Panc-02 cells, preserving normal cells and preventing hemolysis. The innovative approach simultaneously modulated pathways, including VCP/Bip/K48-Ub/ATF6, IRE1α/XBPs/LC3II, PD-L1/TGF-β/IL-10/CD206/MSR1/Arg1, and TNF-α/IFN-γ/IL-6/iNOS/COX-2. Combined treatment blocked VCP, arrested the cell cycle, inhibited EMT, triggered ERS-mediated autophagy/apoptosis, and stimulated robust ICD via the release of damage-associated molecular patterns. This adaptable nanoformulation, displaying pH-sensitive PEG-PGA de-coating and precisely targeting EGFR, PD-L1, and ER, serves to hinder EMT and immune evasion, subsequently amplifying ICD in PDAC cells and the TME.

ZnO-based heterojunction catalysts for the photocatalytic degradation of methyl orange dye

In this study, a variety of ZnO-based heterojunctions with disparate wt.% doping of WO3 and BiOI have been prepared for the photodestruction of methyl orange (MO) dye in aqueous solution. The composites were analysed by scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, optical studies, and nitrogen adsorption-desorption isotherms. The SEM images revealed non-uniform surfaces of the ZnO–BiOI based composites while mostly nodular morphology was observed for all three samples of ZnO-WO3. As the WO3 loading increased, more clustering was detected. The analysed samples exhibited characteristic peaks representative of the triclinic phase of WO3 and the hexagonal wurtzite structure of ZnO, while the diffractogram observed from the materials displayed distinct peaks corresponding to the crystalline phases of both BiOI and ZnO in their pure forms. Further evidence of the samples' characteristics includes the presence of distinct crystalline patterns without any impurity peaks, a red shift in the absorption spectra of the heterostructure, the detection of only the reference elements, and mostly Type IV isotherm adsorption. This study identified the ZnO-[10%]BiOI and ZnO-[10%]WO3 heterojunctions as the best performing photocatalysts, as MO was completely destroyed in 120 and 90 min, respectively. Thus, confirming 10% wt. as the optimal doping concentration for the best photo-activity in this study. The impact of varying process parameters demonstrates that at an elevated photocatalyst mass of 40 mg, both heterojunctions effectively degraded MO. The photodegradation efficiency of MO was more pronounced in strong acidic conditions (pH 2) when compared to high alkaline conditions (pH 11) for the ZnO-[10%]BiOI heterostructure. However, a decrease in performance was observed for both strong acidic and high alkaline pH values when the ZnO-[10%]WO3 heterostructure was applied. The kinetic analysis of the photodegradation study reveals that all the photodegradation experiments can be represented by the pseudo-first-order kinetic model. The findings from this investigation propose that the ZnO-[10%]BiOI heterojunction photocatalyst holds significant potential for the effective treatment of dye-contaminated wastewater.

Fe(III) T1 MRI Probes Containing Phenolate or Hydroxypyridine-Appended Triamine Chelates and a Coordination Site for Bound Water.

Fe(III) complexes containing a triamine framework and phenolate or hydroxypyridine donors are characterized and studied as T1 MRI probes. In contrast to most Fe(III) MRI probes of linear chelates reported to date, the ligands reported here are pentadentate to give six-coordinate complexes with a coordination site for inner-sphere water. The crystal structure of the complex containing unsubstituted phenolate donors, Fe(L1)Cl, shows a six-coordinate iron center and contains a chloride ligand that is displaced in water. Two additional derivatives are sufficiently water-soluble for study as MRI probes, including a complex with a hydroxypyridine group, Fe(L2), and a hydroxybenzoic acid group, Fe(L3). The pH potentiometric titrations give protonation constants of 7.2 and 7.5 for Fe(L2) and Fe(L3), respectively, which are assigned to deprotonation of the bound water. Changes in the electronic absorbance spectra of the complexes as a function of pH are consistent with the deprotonation of phenol pendants at acidic pH values. However, the inner-sphere water ligand of Fe(L2) and Fe(L3) does not exchange rapidly on the NMR timescale at pH 6.0 or 7.4, as shown by variable-temperature 17O NMR spectroscopy. The pH-dependent proton relaxivity profiles show a maximum in relaxivity at a near-neutral pH, suggesting that exchange of the protons of the bound water is an important contribution. Competitive binding studies with ethylenediaminetetraacetic acid (EDTA) show effective stability constants for Fe(L2) and Fe(L3) at pH 7.4 with log K values of 21.1 and 20.5, respectively. These two complexes are kinetically inert in carbonate phosphate buffer at 37 °C for several hours but transfer iron to transferrin. Fe(L2) and Fe(L3) show enhanced contrast in T1-weighted imaging analyses in BALB/c mice. These studies show that Fe(L2) clears through mixed renal and hepatobiliary routes, while Fe(L3) has a similar pharmacokinetic clearance profile to a macrocyclic Gd(III) contrast agent.

Chitosan functionalized with pyrazolinone derivative for water treatment: Application to Hg(II) removal

Due to its high toxicity, the removal of mercury from groundwater in contaminated industrial areas is of critical importance to avoid health problems for living beings. The functionalization of chitosan with pyrazolinone derivative, allows designing a sorbent (CH-PYZ) with high efficiency and selectivity for mercury sorption at acidic pH values (1.40 mmol Hg g−1, at pH 3). The sorbent is characterized by elemental analysis, thermogravimetric and textural analyses (increase in specific surface area and decrease in pore size), Fourier transform infrared spectroscopy, and shift of the pH point of zero charge toward higher value. The sorption was mainly performed through carbonyl, thiocarbonyl, hydroxyl, and amine groups. Under selected experimental conditions, sorption equilibrium is reached in 40 min (faster than crosslinked chitosan, CH) and the kinetic profile is fitted by the pseudo-first order rate equation. The Langmuir equation finely fits sorption isotherms: the functionalization improves both the maximum sorption capacity and the affinity coefficient (by four to six folds). The benefit of the functionalization is also demonstrated by the improved stability of the sorbent at recycling (loss at the fifth cycle does not exceed 2 % for CH-PYZ, against 8 % for CH). The grafting of pyrazolinone derivative brings another advantage in terms of selectivity against other mono-, di- and tri- valent metal ions. The sorbent also preferentially sorbs mercury from groundwater collected in a contaminated area. Under selected experimental conditions, the sorbent allows decontaminating the collected sample for livestock feeding, but the treated water cannot reach the levels for human drinking water.

Exploring Peracetic Acid and Acidic pH Tolerance of Antibiotic-Resistant Non-Typhoidal Salmonella and Enterococcus faecium from Diverse Epidemiological and Genetic Backgrounds.

Acid stress poses a common challenge for bacteria in diverse environments by the presence of inorganic (e.g., mammals' stomach) or organic acids (e.g., feed additives; acid-based disinfectants). Limited knowledge exists regarding acid-tolerant strains of specific serotypes, clonal lineages, or sources in human/animal pathogens: namely, non-typhoidal Salmonella enterica (NTS) and Enterococcus faecium (Efm). This study evaluated the acidic pH (Mueller-Hinton acidified with HCl) and peracetic acid (PAA) susceptibility of Efm (n = 72) and NTS (n = 60) from diverse epidemiological/genetic backgrounds and with multiple antibiotic resistance profiles. Efm minimum growth/survival pH was 4.5-5.0/3.0-4.0, and for NTS it was 4.0-4.5/3.5-4.0. Efm distribution among acidic pH values showed that only isolates of clade-non-A1 (non-hospital associated) or the food chain were more tolerant to acidic pH compared to clade-A1 (hospital-associated clones) or clinical isolates (p < 0.05). In the case of NTS, multidrug-resistant (MDR) isolates survived better in acidic pH (p < 0.05). The PAA MIC/MBC for Efm was 70-120/80-150 mg/L, and for NTS, it was 50-70/60-100 mg/L. The distribution of Efm among PAA concentrations showed that clade-A1 or MDR strains exhibited higher tolerance than clade-non-A1 or non-MDR ones (p < 0.05). NTS distribution also showed higher tolerance to PAA among non-MDR and clinical isolates than food chain ones (p < 0.05) but there were no differences among different serogroups. This unique study identifies specific NTS or Efm populations more tolerant to acidic pH or PAA, emphasizing the need for further research to tailor controlled measures of public health and food safety within a One Health framework.

Assessing the Activity under Different Physico-Chemical Conditions, Digestibility, and Innocuity of a GAPDH-Related Fish Antimicrobial Peptide and Analogs Thereof.

The antimicrobial activity of SJGAP (skipjack tuna GAPDH-related antimicrobial peptide) and four chemical analogs thereof was determined under different physicochemical conditions, including different pH values, the presence of monovalent and divalent cations, and after a heating treatment. The toxicity of these five peptides was also studied with hemolytic activity assays, while their stability under human gastrointestinal conditions was evaluated using a dynamic in vitro digestion model and chromatographic and mass spectrometric analyses. The antibacterial activity of all analogs was found to be inhibited by the presence of divalent cations, while monovalent cations had a much less pronounced impact, even promoting the activity of the native SJGAP. The peptides were also more active at acidic pH values, but they did not all show the same stability following a heat treatment. SJGAP and its analogs did not show significant hemolytic activity (except for one of the analogs at a concentration equivalent to 64 times that of its minimum inhibitory concentration), and the two analogs whose digestibility was studied degraded very rapidly once they entered the stomach compartment of the digestion model. This study highlights for the first time the characteristics of antimicrobial peptides from Scombridae or homologous to GAPDH that are directly related to their potential clinical or food applications.

Probiotic Lactobacillus strains isolated from date waste and wastewater for the kidney stone, intestinal oxalate-degradation and antioxidant activity

Lactic acid bacteria (LAB) are probiotic organisms and are promising alternatives to manage kidney stone problems. Oxalate digesting LAB was screened from date wastes and date wastewater. LAB was isolated using De Man, Rogosa and Sharpe agar (MRS agar) medium and was subjected to oxalate degradation assay in a calcium oxalate plate. The strain was further subjected to assay for its capacity to tolerate acidic pH value and bile salt. Then, anti-urolithiatic activity assay was carried out by in vitro analysis. Based on preliminary characteristics, among 62 oxalate degrading strains, twenty-four strains exhibited a greater than 10 mm zone. The potent bacterial strains were identified as Lactobacillus cassei, L. acidophilus, L. gasseri and L. fermentum. Isolates from date wastes showed better antagonistic properties towards bacterial pathogens. At 50 µg Calcium oxalate concentration, 75.6 ± 0.865 degradation was achieved by L acidophilus. LAB isolated from date waste showed promising anti-urolithiasis activity. Hence, date waste may serve as a potential source for LAB probiotics to treat hyperoxaluria.

Effect of pH on Cytomorphological Parameters of Erythrocytes of the &lt;i&gt;Rana macrocnemis&lt;/i&gt; Tadpoles

The article presents the results of studies of the effect of acidic (4.0, 5.0) and alkaline (9.0) pH values on cytomorphological parameters of erythrocytes of Rana macrocnemis tadpoles. The negative effect of pH 4.0 on the cytomorphological features of erythrocytes is shown, expressed in a decrease in their geometric parameters (area, volume), which leads to a deterioration of their function. Changes in the linear and geometric parameters of tadpole blood cells when exposed to pH 5.0 and 9.0 in both series of the experiment allow us to judge their focus on improving the efficiency of oxygen transport, that is, they are compensatory in nature.

Benzidine Derivatives as Electroactive Materials for Aqueous Organic Redox Flow Batteries.

This paper presents a theoretical and experimental evaluation of benzidine derivatives as electroactive molecules for organic redox flow batteries. These redox indicators are novel electroactive materials that can perform multielectron transfers in aqueous media. We performed the synthesis, electrochemical characterization, and theoretical study of the dimer of sodium 4-diphenylamine sulfonate, a benzidine derivative with high water solubility properties. The Pourbaix diagram of the dimer shows a bielectronic process at highly acidic pH values (≤ 0.9) and two single-electron transfers in a pH range from 0 to 9. The dimer was prepared in situ and tested on a neutral electrochemical flow cell as a stability diagnostic. To improve cell performance, we calculate and calibrate, with experimental data, the Pourbaix diagrams of benzidine derivatives using different substitution patterns and functional groups. A screening process allowed the selection of those derivatives with a bielectronic process in the entire pH window or at acidic/neutral pH values. Given the redox potential difference, they can be potential catholytes or anolytes in a flow cell. The couples formed with the final candidates can generate a theoretical cell voltage of 0.60 V at pH 0 and up to 0.68 V at pH 7. These candidate molecules could be viable as electroactive materials for a full-organic redox flow battery.

Green modified-UiO-66/MXene sandwich composites for gene-chemotherapy synergistic cancer suppression: Co-delivery of doxorubicin and pCRISPR

Advancements in material science and engineering, especially in the field of porous nanomaterials lead to new types of therapeutics and technologies. Among different types of porous nanomaterials, metal–organic frameworks (MOFs) have been considered the most promising inorganic nanomaterials due to their significant stability and ease of functionalization. To date, very limited research has been done on developing nanocomposites based on MOFs and MXenes. The current experiment has been performed to design a novel UiO-66 MOF and MXene nanocomposite, modified with Rosmarinus officinalis (RO) leaf extracts for co-delivery of doxorubicin (DOX)/clustered regularly interspaced short palindromic repeats (CRISPR). The synthesis procedure was completed with the assistance of a high-gravity system and a rotating packed bed (RPB) device for the first time, and the characterization results showed the successful synthesis of the nanomaterials. Based on the drug release and loading results, the DOX payload efficiency of about 46% was recorded, and sustained drug release at acidic pH values (same as the cancerous cells) was observed. However, the presence of leaf extracts slowed down the drug release and have a minor effect on the release profiles, the cellular internalization results on the MCF-7 and HT-29 cell lines showed considerably dependent images. The gene transfections result by using two nanosystems of UiO-66@MXene@RO@DOX@pCRISPR, and UiO-66@MXene@RO@DOX@RO@pCRISPR showed about 18.3% and 22.1% transfection efficiency on the A549 cell lines. Those results showed no heavily dependent results on the presence or absence of the leaf extracts. Therefore, this study revealed that the green modification of nanocomposites does have a major effect only on the cellular internalizations of DOX, rather than CRISPR.

Octenyl succinic anhydride-modified amyloid protein fibrils demonstrate enhanced ice recrystallization inhibition activity and dispersibility

Octenyl succinic anhydride (OSA) modification of amyloid proteins fibrils (APFs) was employed to improve dispersibility and ice recrystallization inhibition activity. OSA mainly reacted with the amino groups of APFs without significantly changing morphology. OSA-modified APFs (OAPFs) had lower pI, carried more negative charges, and were more hydrophobic. OSA-modification showed a pH-dependent effect on the dispersibility of fibrils. At pH 7.0, OSA-modification improved dispersibility and inhibited heat-induced gelation of fibrils at weakened electrostatic repulsion. OAPFs were more prone to aggregation with lower dispersity at acidic pH values and demonstrated stronger IRI activity than unmodified fibrils at pH 7.0. Our findings indicate OSA-modification favors the industrial application of APFs as an ice recrystallization inhibitor with enhanced dispersibility.

Assessing the Versatility of Bioextraction to Preserve Waterlogged Wood

An innovative bio method was investigated to extract harmful iron and sulfur species from waterlogged wood samples. The method was compared with a chemical treatment. Both approaches were applied on lacustrine and marine samples, from different wood genera, to evaluate the versatility of the proposed bio method. Non-invasive and non-destructive methods were carried out to investigate both bio-based and chemical treatments. The result was that some wood genera were more affected by the bio approach, with a clear distinction between lacustrine beech and pine against oak and lime wood species. The chemical approach showed potential harm for the wooden structure, with acidic pH values and an increase of maximum water content, both implying degradation of the wood structure. In terms of extraction, no iron or sulfur products were detected by Raman spectroscopy on biologically treated samples, in agreement with extraction rates calculated. It was also suggested that iron bonded to wood was extracted with the chemical approach, and calcium content affected by both approaches.

The occurrence and resistance of Shigella flexneri CECT4804 to acid stress in vitro and in vivo.

The ability to maintain intra‑cellular pH is crucial for many microbes mainly the enterobacteria to survive in diverse environments, particularly those that undergo fluctuations in pH. In this context, the growth and survival of Shigella flexneri at different acid pH values were evaluated to explain the response strategies involved in the adaptation of S. flexneri CECT4804 in acid stress conditions. Furthermore, the capacity of this strain to produce slime on Congo Red Agar, biofilm formation on polystyrene plate and hydrophobicity are reported. In addition, the modification of the membrane fatty acids profiles has been studied. Moreover, an infection with the stressed strain was realized on rats in rates and examined for their toxicity in intestine tissue. The obtained results show that the strain survival is strongly influenced by acidity. Indeed, the stressed and unstressed strains became biofilm positive after acid stress. A significant increase in the hydrophobicity percentage compared to the values found under normal conditions, is also noticed. For the membrane fatty acids analysis, the acidity induces several modifications in the membrane composition. After the infection, the gravest lesion was registered in the intestine of rats administered with the bacteria stressed at the lowest pH.

The Effect of Lyophilized and Frozen Natural Lactic Acid Bacteria on Alfalfa Silage Quality Prepared in Different Ways and Stored for Different Periods of Time

Within the scope of this study, it was aimed to determine the effect of the groups with the highest LAB numbers determined as a result of storage for one and three months on alfalfa silage quality by freezing fermented lactic acid bacteria (LAB) liquids prepared with different levels of sucrose addition (5-10%) and incubation (2 and 5 days) for different periods of time in deep freezer and by drying via lyophilization process according to the results obtained from the previous study.In the study, groups consisted of control, 2D5%STsL (lyophilized with TRIS (Ts) after 2 days incubation with 5% sucrose addition), 2D10%SDsL (lyophilized with DMSO (Ds) after 2 days incubation with 10% sucrose addition), 5D10%SDsL (DMSO (Ds) additive lyophilized after 5 days of incubation with 10% sucrose addition), and 5D5%STsD (TRIS (Ts) additive deep freezer after 5 days of incubation with 5% sucrose addition).In the study, LAB count, CO2, lactic acid (LA) content, acetic acid (AA) content, pH, NH3-N/TN, and butyric acid (BA) values were statistically significant between the groups at the end of the one-month storage period. Crude protein (CP), pH, LA, and BA values were found to be statistically significant between the groups at the end of the three-month storage period in the study.